<?php

/**
 * This is the model class for table "tag".
 *
 * The followings are the available columns in table 'tag':
 * @property integer $id
 * @property string $name
 * @property integer $frequency
 *
 * The followings are the available model relations:
 */
class Tag extends CActiveRecord
{
	/**
	 * Returns the static model of the specified AR class.
	 * @return Tag the static model class
	 */
	public static function model($className=__CLASS__)
	{
		return parent::model($className);
	}

	/**
	 * @return string the associated database table name
	 */
	public function tableName()
	{
		return '{{tag}}';
	}

	/**
	 * @return array validation rules for model attributes.
	 */
	public function rules()
	{
		// NOTE: you should only define rules for those attributes that
		// will receive user inputs.
		return array(
			array('name, frequency', 'required'),
			array('frequency', 'numerical', 'integerOnly'=>true),
			array('name', 'length', 'max'=>64),
			// The following rule is used by search().
			// Please remove those attributes that should not be searched.
			array('id, name, frequency', 'safe', 'on'=>'search'),
		);
	}

	/**
	 * @return array relational rules.
	 */
	public function relations()
	{
		// NOTE: you may need to adjust the relation name and the related
		// class name for the relations automatically generated below.
		return array(
		);
	}

	/**
	 * @return array customized attribute labels (name=>label)
	 */
	public function attributeLabels()
	{
		return array(
			'id' => 'ID',
			'name' => 'Name',
			'frequency' => 'Frequency',
		);
	}

	/**
	 * Retrieves a list of models based on the current search/filter conditions.
	 * @return CActiveDataProvider the data provider that can return the models based on the search/filter conditions.
	 */
	public function search()
	{
		// Warning: Please modify the following code to remove attributes that
		// should not be searched.

		$criteria=new CDbCriteria;

		$criteria->compare('id',$this->id);
		$criteria->compare('name',$this->name,true);
		$criteria->compare('frequency',$this->frequency);

		return new CActiveDataProvider(get_class($this), array(
			'criteria'=>$criteria,
		));
	}
	
	public static function string2array($str)
	{
		return preg_split('/\s*,\s*|\s+/', $str, -1, PREG_SPLIT_NO_EMPTY);
	}
	
	public static function array2string($arr)
	{
		return implode(',', $arr);
	}
	
	public function updateFrequency($newTags, $oldTags)
	{
		$newTags = self::string2array($newTags);
		$oldTags = self::string2array($oldTags);
		$this->addTags(array_diff($newTags, $oldTags));
		$this->removeTags(array_diff($oldTags, $newTags));
	}
	
	public function addTags(array $tags)
	{
		$criteria = new CDbCriteria;
		$criteria->addInCondition('name', $tags);
		$this->updateCounters(array('frequency' => 1), $criteria);	//Checks whether there is row satisfying the specified condtion;
		foreach ($tags as $name) {
			if (!$this->exists('name = :name', array(':name' => $name))) {
				$tag = new Tag;
				$tag->name = $name;
				$tag->frequency = 1;
				$tag->save();
			}
		}
	}
	
	/**
	 * remove tag
	 * @param array $tags
	 */
	public function removeTags(array $tags) 
	{
		if (empty($tags))
			return;
		$criteria = new CDbCriteria;
		$criteria->addInCondition('name', $tags);
		$this->updateCounters(array('frequency' => -1), $criteria);
		$this->deleteAll('frequency<=0');
	}
	
	/**
	 * fine tags by weight
	 * @param int $maxTags
	 */
	public function findTagWieghts($maxTags)
	{
		$models = $this->findAll(array(
			'order' => 'frequency DESC',
			'limit' => $maxTags,
		));
		
		return $models;
	}
}